Railtrack heaters are often utilized on areas of track rails where it is desirable that the track be devoid of snow, ice and/or moisture. One such area is around sensors (e.g., infrared sensors) that are mounted relative to track rails to detect hot boxes on passing trains. A hot box occurs when the bearings between an axle and wheel (i.e., the box) of a particular train car heat to an excessive temperature that may allow the bearings to fail. Hot boxes present a fire hazard and can lead to the fracturing of the axle and possibly train derailment. Where an infrared sensor monitors a hot box on a passing train, a train engineer may receive a signal originating from the sensor indicating the need to take corrective action. However, if such a sensor is covered with snow or ice or, for example, develops a fogged lens, the sensor may not function for its intended purpose.
Another area where it is desirable to reduce or eliminate snow build up is around railroad track switches. In order to ensure proper functioning of a railroad track switch, it is important that the switching rail (e.g., tapered movable rail, point blade) and stationary rail make good contact when in an engaged position. Accordingly, in cold climates, it is common to heat the rail switch or otherwise guard against buildup of ice or snow at the switch, especially at the interface between the gauge side of the stationary rail and field side of the switching rail. Furthermore, it is also common to heat railroad frogs (e.g., movable point frogs, stationary frogs) as the buildup of ice and/or snow could otherwise inhibit a train wheel from properly crossing over a rail at a rail junction. Malfunctioning of the switch due to such build up presents a danger of derailment potentially resulting in personal injury and/or property damage.
Typically, railroad track heaters provide conductive heat to the rails by being directly mounted and in contact with the rails. One such heater is described in U.S. Pat. No. 5,824,997, the content of which is incorporated herein by reference. Generally, such heaters include a metal jacket that is mounted directly to a rail to maximize thermal conductivity between the heater and the rail.